package com.hotbitmapgg.moequest.widget;

import android.support.v4.view.ViewPager;
import android.view.View;

/**
 * Created by hcc on 16/6/25 17:23
 * 100332338@qq.com
 * <p/>
 * Google官方ViewPager切换动画
 */
public class DepthTransFormes implements ViewPager.PageTransformer {

  private static final float MIN_SCALE = 0.75f;


  public void transformPage(View view, float position) {

    int pageWidth = view.getWidth();

    if (position < -1) { // [-Infinity,-1)
      // This page is way off-screen to the left.
      view.setAlpha(0);
    } else if (position <= 0) { // [-1,0]
      // Use the default slide transition when moving to the left page
      view.setAlpha(1);
      view.setTranslationX(0);
      view.setScaleX(1);
      view.setScaleY(1);
    } else if (position <= 1) { // (0,1]
      // Fade the page out.
      view.setAlpha(1 - position);

      // Counteract the default slide transition
      view.setTranslationX(pageWidth * -position);

      // Scale the page down (between MIN_SCALE and 1)
      float scaleFactor = MIN_SCALE
          + (1 - MIN_SCALE) * (1 - Math.abs(position));
      view.setScaleX(scaleFactor);
      view.setScaleY(scaleFactor);
    } else { // (1,+Infinity]
      // This page is way off-screen to the right.
      view.setAlpha(0);
    }
  }
}
